package com.aaa.redis;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class ApplicationContextHolder implements ApplicationContextAware {
    private static ApplicationContext applicationContext;

    /*** 实现ApplicationContextAware接口的context注入函数, 将其存入静态变量. */
    public void setApplicationContext(ApplicationContext applicationContext) {
        ApplicationContextHolder.applicationContext = applicationContext; // NOSONAR }
    }
    /**
     2.3.2 重写Mybatis配置类
     * 取得存储在静态变量中的ApplicationContext. */
    public static ApplicationContext getApplicationContext() {
        checkApplicationContext();
        return applicationContext;
    }

    /*** 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型. */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) {
        checkApplicationContext();
        return (T) applicationContext.getBean(name);
    }

    /*** 从静态变量ApplicationContext中取得Bean, 自动转型为所赋值对象的类型. */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(Class<T> clazz) {
        checkApplicationContext();
        return (T) applicationContext.getBeansOfType(clazz);
    }

    /*** 清除applicationContext静态变量. */
    public static void cleanApplicationContext() {
        applicationContext = null;
    }

    private static void checkApplicationContext() {
        if (applicationContext == null) {
            throw new IllegalStateException("applicaitonContext未注入,请在 applicationContext.xml中定义SpringContextHolder");
        }
    }
}